1. Field of the Invention
This invention relates to a bicycle frame, more particularly to a bicycle frame with a seat that is adjustable in forward, backward, upward and downward directions.
2. Description of the Related Art
A conventional bicycle frame has a fixed seat tube for mounting a seat thereon. Although the seat is extendable and retractable relative to the seat tube so as to adjust the height of the seat, the seat tube can not be moved to adjust the seat forward and backward, thereby resulting in discomfort for some users.